// class template regex -*- C++ -*- // Copyright (C) 2013-2020 Free Software Foundation, Inc. // // This file is part of the GNU ISO C++ Library. This library is free // software; you can redistribute it and/or modify it under the // terms of the GNU General Public License as published by the // Free Software Foundation; either version 3, or (at your option) // any later version. // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // Under Section 7 of GPL version 3, you are granted additional // permissions described in the GCC Runtime Library Exception, version // 3.1, as published by the Free Software Foundation. // You should have received a copy of the GNU General Public License and // a copy of the GCC Runtime Library Exception along with this program; // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see // <http://www.gnu.org/licenses/>. /** * @file bits/regex_automaton.tcc * This is an internal header file, included by other library headers. * Do not attempt to use it directly. @headername{regex} */ namespace std _GLIBCXX_VISIBILITY(default) { _GLIBCXX_BEGIN_NAMESPACE_VERSION namespace __detail { #ifdef _GLIBCXX_DEBUG inline std::ostream& _State_base::_M_print(std::ostream& ostr) const { switch (_M_opcode) { case _S_opcode_alternative: case _S_opcode_repeat: ostr << "alt next=" << _M_next << " alt=" << _M_alt; break; case _S_opcode_subexpr_begin: ostr << "subexpr begin next=" << _M_next << " index=" << _M_subexpr; break; case _S_opcode_subexpr_end: ostr << "subexpr end next=" << _M_next << " index=" << _M_subexpr; break; case _S_opcode_backref: ostr << "backref next=" << _M_next << " index=" << _M_backref_index; break; case _S_opcode_match: ostr << "match next=" << _M_next; break; case _S_opcode_accept: ostr << "accept next=" << _M_next; break; default: ostr << "unknown next=" << _M_next; break; } return ostr; } // Prints graphviz dot commands for state. inline std::ostream& _State_base::_M_dot(std::ostream& __ostr, _StateIdT __id) const { switch (_M_opcode) { case _S_opcode_alternative: case _S_opcode_repeat: __ostr << __id << " [label=\"" << __id << "\\nALT\"];\n" << __id << " -> " << _M_next << " [label=\"next\", tailport=\"s\"];\n" << __id << " -> " << _M_alt << " [label=\"alt\", tailport=\"n\"];\n"; break; case _S_opcode_backref: __ostr << __id << " [label=\"" << __id << "\\nBACKREF " << _M_subexpr << "\"];\n" << __id << " -> " << _M_next << " [label=\"<match>\"];\n"; break; case _S_opcode_line_begin_assertion: __ostr << __id << " [label=\"" << __id << "\\nLINE_BEGIN \"];\n" << __id << " -> " << _M_next << " [label=\"epsilon\"];\n"; break; case _S_opcode_line_end_assertion: __ostr << __id << " [label=\"" << __id << "\\nLINE_END \"];\n" << __id << " -> " << _M_next << " [label=\"epsilon\"];\n"; break; case _S_opcode_word_boundary: __ostr << __id << " [label=\"" << __id << "\\nWORD_BOUNDRY " << _M_neg << "\"];\n" << __id << " -> " << _M_next << " [label=\"epsilon\"];\n"; break; case _S_opcode_subexpr_lookahead: __ostr << __id << " [label=\"" << __id << "\\nLOOK_AHEAD\"];\n" << __id << " -> " << _M_next << " [label=\"epsilon\", tailport=\"s\"];\n" << __id << " -> " << _M_alt << " [label=\"<assert>\", tailport=\"n\"];\n"; break; case _S_opcode_subexpr_begin: __ostr << __id << " [label=\"" << __id << "\\nSBEGIN " << _M_subexpr << "\"];\n" << __id << " -> " << _M_next << " [label=\"epsilon\"];\n"; break; case _S_opcode_subexpr_end: __ostr << __id << " [label=\"" << __id << "\\nSEND " << _M_subexpr << "\"];\n" << __id << " -> " << _M_next << " [label=\"epsilon\"];\n"; break; case _S_opcode_dummy: break; case _S_opcode_match: __ostr << __id << " [label=\"" << __id << "\\nMATCH\"];\n" << __id << " -> " << _M_next << " [label=\"<match>\"];\n"; break; case _S_opcode_accept: __ostr << __id << " [label=\"" << __id << "\\nACC\"];\n" ; break; default: _GLIBCXX_DEBUG_ASSERT(false); break; } return __ostr; } template<typename _TraitsT> std::ostream& _NFA<_TraitsT>::_M_dot(std::ostream& __ostr) const { __ostr << "digraph _Nfa {\n" " rankdir=LR;\n"; for (size_t __i = 0; __i < this->size(); ++__i) (*this)[__i]._M_dot(__ostr, __i); __ostr << "}\n"; return __ostr; } #endif template<typename _TraitsT> _StateIdT _NFA<_TraitsT>::_M_insert_backref(size_t __index) { if (this->_M_flags & regex_constants::__polynomial) __throw_regex_error(regex_constants::error_complexity, "Unexpected back-reference in polynomial mode."); // To figure out whether a backref is valid, a stack is used to store // unfinished sub-expressions. For example, when parsing // "(a(b)(c\\1(d)))" at '\\1', _M_subexpr_count is 3, indicating that 3 // sub expressions are parsed or partially parsed(in the stack), aka, // "(a..", "(b)" and "(c.."). // _M_paren_stack is {1, 3}, for incomplete "(a.." and "(c..". At this // time, "\\2" is valid, but "\\1" and "\\3" are not. if (__index >= _M_subexpr_count) __throw_regex_error( regex_constants::error_backref, "Back-reference index exceeds current sub-expression count."); for (auto __it : this->_M_paren_stack) if (__index == __it) __throw_regex_error( regex_constants::error_backref, "Back-reference referred to an opened sub-expression."); this->_M_has_backref = true; _StateT __tmp(_S_opcode_backref); __tmp._M_backref_index = __index; return _M_insert_state(std::move(__tmp)); } template<typename _TraitsT> void _NFA<_TraitsT>::_M_eliminate_dummy() { for (auto& __it : *this) { while (__it._M_next >= 0 && (*this)[__it._M_next]._M_opcode() == _S_opcode_dummy) __it._M_next = (*this)[__it._M_next]._M_next; if (__it._M_has_alt()) while (__it._M_alt >= 0 && (*this)[__it._M_alt]._M_opcode() == _S_opcode_dummy) __it._M_alt = (*this)[__it._M_alt]._M_next; } } // Just apply DFS on the sequence and re-link their links. template<typename _TraitsT> _StateSeq<_TraitsT> _StateSeq<_TraitsT>::_M_clone() { std::map<_StateIdT, _StateIdT> __m; std::stack<_StateIdT> __stack; __stack.push(_M_start); while (!__stack.empty()) { auto __u = __stack.top(); __stack.pop(); auto __dup = _M_nfa[__u]; // _M_insert_state() never return -1 auto __id = _M_nfa._M_insert_state(std::move(__dup)); __m[__u] = __id; if (__dup._M_has_alt()) if (__dup._M_alt != _S_invalid_state_id && __m.count(__dup._M_alt) == 0) __stack.push(__dup._M_alt); if (__u == _M_end) continue; if (__dup._M_next != _S_invalid_state_id && __m.count(__dup._M_next) == 0) __stack.push(__dup._M_next); } for (auto __it : __m) { auto __v = __it.second; auto& __ref = _M_nfa[__v]; if (__ref._M_next != _S_invalid_state_id) __ref._M_next = __m.find(__ref._M_next)->second; if (__ref._M_has_alt() && __ref._M_alt != _S_invalid_state_id) __ref._M_alt = __m.find(__ref._M_alt)->second; } return _StateSeq(_M_nfa, __m[_M_start], __m[_M_end]); } } // namespace __detail _GLIBCXX_END_NAMESPACE_VERSION } // namespace